1. Field of the Invention
This invention relates generally to coverings for architectural openings and more particularly to a cord tensioner for mounting in an architectural opening and for securing the lower extent of an endless operating element or cord used to operate the covering.
2. Description of the Relevant Art
Coverings for architectural openings have taken numerous forms through the many years they have been used for covering windows, doors, archways, or the like. Early forms of such coverings consisted simply of fabric materials draped across an architectural opening while more recent forms of covering have included retractable coverings such as venetian blinds, vertical blinds, cellular shades, and the like.
Retractable coverings are typically operated with a control cord that is operatively connected to a control system in a headrail for the covering with control cords assuming several different variations. A single cord can depend from one end of the headrail and can be moved up and down to operate the covering and move it between open and closed conditions and/or between retracted and extended conditions. A pair of control cords can also depend from the headrail in a similar manner again for manipulating the covering between different conditions.
Some coverings for architectural openings are operated with an endless flexible element such as a cord, tape, or chain that cooperates with a control system in the headrail for operating the covering and hangs from a headrail in an endless loop so that one run of the depending endless loop can be pulled downwardly while the other run moves upwardly to operate the covering. It has been found desirable with endless operating elements that securing or anchoring the lower extent of the endless element adjacent the bottom of the architectural opening makes the covering easier to operate and is aesthetically more attractive as there are no dangling elements but rather suitably tensioned elements confined between the headrail and an anchor at the bottom of the architectural opening. Anchors at the bottom of the architectural opening are sometimes referred to as tensioners as they typically have resilient means for biasing the endless control element into a desirably taut condition.
It is to provide improvements in tensioners for endless operating elements for coverings for architectural openings that the present invention has been developed.